This invention relates a system that operates from the expansion energy of a substance when the substance is transformed from one state to another state, and more specifically, to a device that operates from the expansion force of a substance as the substance increases in volume when transformed from a liquid to a solid state.
A substance that increases in volume, or expands, when transformed from a liquid to a solid state is water. As water freezes, it increases its volume by approximately 10%, depending on various conditions. Further, the maximum pressure available from the expansion of water when the water is transformed to ice is approximately 30,000 psi. The idea of utilizing the expansion of water as it freezes to produce a work is known. Efforts to effectively utilize this expansion energy, however, have generally been ineffective, or unsuccessful. The prior art methods have not been successful partially due to the length of the freeze and thaw cycle of water, and partially due to inefficiencies of the prior art systems in utilizing the energy available from the freezing forces of water.
In order to be of practical use, a system must be able to effectively and efficiently utilize the natural and artificial sources of cooling and heating to facilitate the temperature change of the water. Additionally, a system is more effective if it is able to draw usable energy from only the freezing portion of the freeze/thaw cycle of water. Finally, a system must have the capability of storing the energy available for a period of time before use.
The object of the present invention is to provide a system which effectively and efficiently extracts energy from the expansion forces produced by water as it freezes using naturally and artificially available sources of cooling and heating. Another object of the invention is to provide a system able to operate from either passive or active exposure to available sources of cooling and heating. Another object of this invention is to provide a system which can effectively operate only from the freezing of water when forming ice. A further object of the invention is to provide a system that allows the energy extracted to be used at a later time.